Present day chicken or poultry houses are normally equipped with a plurality of cages having water containers with normally closed valves connecting the containers to a water supply. Certain of such valves are adapted to be opened by a valve actuator in the container which is operated by the chicken pecking or pushing on the actuator, which may be a stem extending from the valve into the container. Difficulties have been had with such valves for several reasons; the chickens may never learn to move the stem and the valve may become clogged with feed or foreign matter which interferes with its operation.
In my prior U.S. Pat. No. 3,483,847, a poultry watering cup is disclosed having a valve construction designed to overcome the foregoing difficulties. The valve shown therein has a double seat to effect a better and more positive seal, and the valve stem is positioned to extend down into a relatively small cup so that as the water lever therein is lowered the chicken will unconsciously tilt the stem as it drinks and open the valve to admit water into the cup.
However, I have discovered that the construction of U.S. Pat. No. 3,483,847 was not entirely satisfactory under certain conditions. The two valve seats shown therein are stepped flat surfaces on one of which the flat shoulder of the head of the valve seats, and on the other a flat disk valve seats. A flat valve disk will seal tightly against a flat seat only at high or medium water pressure, and it is very important to provide for a tight seal at low water pressure as today millions of day old chicks are started in cages and they can activate the water cups only at very low water pressure. Moreover, the seats become contaminated by any foreign matter carried in the water supply. Further, in the event the pressure of the water supply is lost and a leak occurs in the system tending to siphon drinking water from above the cup, the space above the upper valve disk is such as to allow it to lift off its seat and become wedged in the internal threads to the extent that it may not prevent siphoning. The result may be that feed particles from the cup become lodged under the valves causing them to leak, and bacteria and feed particles will contaminate the water feed lines, requiring replacement of the entire water system.